I'm about 25% completed as far as all the side stuff and random stuff to find. I really, really enjoy it. I absolutely hated GTA4. This game is exactly what I wanted from open world crime.
I really like movies like Infernal Affairs, Bittersweet Life, and Old Boy and this definitely has the same mood with Hong Kong (although those are Korean), undercover cop in the criminal underground, the shootouts and the giant brawls. They did a great job replicating the Batman melee formula and it's a ton of fun. Some of these environment kills are brutal. I was in a fish market and threw dudes up on hanging hooks and impaled them on swordfish heads. The driving in this game is excellent and you can hijack vehicles from another vehicle. The story is pretty solid. Even some quality voice over work. Whoever voices Wei Shen is a bad ass. Lucy Lui, Emma Stone (although I haven't heard from her in a long time) and Tom Wilkinson do a great job. You can definitely relate to the way you interact with the characters that Wei Shen meets as he forms bonds with these guys. All around great game so far. This was the 1st game I pre-ordered all year and it's been worth my money so far.